JPH0816516B2 - Repairing method of pipe having branch pipe - Google Patents

Description

The present invention relates to a method for repairing piping. More specifically, the present invention relates to a pipe repairing method capable of easily and quickly repairing a pipe having a branch pipe, reducing resistance to fluid in the pipe, and effectively preventing corrosion of the pipe. Is.

[Prior Art] Water pipes, gas pipes, and various other buried pipes rust on the inner surface with long-term use, or water stains and dust adhere to form rust bumps and scales, Decrease and increase of friction coefficient occur. It is well known that this causes problems such as pressure loss of the fluid, reduction of the flow rate, generation of red water, etc., and the function as a pipe is completely impaired.

Moreover, underground buried pipes require a great deal of labor and cost, such as finding leaks, repairing pipes by excavation, replacing new pipes, and backfilling excavated parts. Due to problems such as traffic obstacles and construction noise over a period of time, new pipe exchange work is becoming increasingly difficult.

For that purpose, effectively utilize the old pipes that have deteriorated, insert polyethylene pipes with a slightly smaller diameter into the existing pipes in consideration of shortening the construction period, economic efficiency, resource saving, etc. A method of repairing a pipe for injecting cement milk has been proposed.

However, this kind of repair method is very effective if it is a straight pipe, but it is a curved pipe (L pipe) or branch pipe (T pipe).
Does not give satisfactory results.

Therefore, in order to repair such parts, a short pipe with a flange coated with synthetic resin powder or a lined pipe is often used.Flanges are attached to both ends of the existing pipe, and the inner surface is prepared in advance. It is connected by a short pipe with a flange coated with synthetic resin powder or lined with a synthetic resin sleeve, and the outer surfaces of the curved pipe and the branch pipe are buried with anticorrosion tape or jute winding. Therefore, after repairing, unreliable defects such as loosening of bolts and nuts and leakage from the gasket surface will occur.Therefore, in the method of attaching such a member to the buried pipe, the reliability of the construction method itself is low, and the construction period and It is also disadvantageous in terms of equipment costs.

[Problems to be Solved by the Invention] The present invention focuses on the above situation and aims to solve these conventional drawbacks.

That is, the present invention provides a method for easily and quickly repairing a branch pipe portion of a pipe having a branch pipe, at low cost, and reliably.

[Means for Solving Problems] That is, according to the method of the present invention, a part of an aged pipe having a branch pipe is cut to remove an internal scale and a rust lump, and then a synthetic resin is applied to the main pipe portion. In the state where the repair pipe made of plastic is inserted, a repair branch pipe made of synthetic resin having a slightly smaller diameter than the branch pipe is inserted from the outside of the branch pipe, and the repair pipe is held while the original shape of the repair pipe is held by the original shape holding means. After heat-sealing the branch pipe to the outside of the repair pipe, the space between the repair pipe and the main pipe is filled with a curing agent or the like, and then the blind part of the repair branch pipe is opened from the outside of the branch pipe. It is characterized by that.

Further, in the above repair method, for example, a small opening is provided in a portion where the repair pipe is exposed in the branch pipe, an expansion bag is inserted into the repair pipe through the small opening, and by expanding the inside of the repair pipe, When the repair branch pipe is heat-sealed to the repair pipe, the original shape of the repair pipe is retained to ensure the heat-sealing.

[Operation] According to the method of the present invention, since an existing branch pipe can be used as it is and a synthetic resin pipe can be integrally incorporated, the construction can be performed easily and quickly, and after repairing, the main pipe Also, both the branch pipe and the branch pipe can form a pipe wall having a smooth inner surface and low resistance, so that it is possible to increase the flow rate and prevent inner surface corrosion and electrolytic corrosion. Further, according to the method of the present invention, it is possible to reduce the construction period and cost.

[Examples] The present invention will be described in more detail based on the illustrated examples. The embodiments are merely representative examples, and in addition to the above description and the following embodiments, various modes can be modified and implemented. All of these belong to the technical scope of the present invention. Further, in the following embodiments, an example of a buried existing pipe will be described, but the present invention can be applied to repairing a ground pipe and lining a new pipe.

First, referring to FIG. 1, an outline of the process of repairing an existing pipe using a repair pipe made of synthetic resin will be described taking an underground buried pipe as an example.

Vertical shafts 2 are excavated at appropriate distances on both sides of the buried pipe 1 to be repaired. Next, the buried pipe 1 exposed in the vertical shaft 2
Is cut into a certain length, and the opening of the buried pipe 1 is provided.

After that, depending on the state of rust and dirt inside the buried pipe 1, an auger or the like is inserted through the opening on one side to perform preliminary cleaning of the repair section. When the repair section is long, preliminary cleaning by pig cleaning is economical and preferable. In addition, depending on the state after the preliminary cleaning, scrapes and scales stuck in the pipe are scraped off with a scraper or a wire brush, and cleaning such as washing with water is performed. However, it is not necessary to completely remove the rust, and cleaning may be performed so that the repair pipe can be smoothly inserted into the buried pipe.

After the cleaning of the interior of the buried pipe 1 is completed, a rope 4 inserted beforehand is attached to the tip of the repair pipe 3 made of synthetic resin, and an opening on the insertion side of the repair pipe 3 is provided with a winch 5 or the like. From the above, the repair pipe 3 is inserted into the buried pipe 1 by pulling toward the opening of the other end.

Next, the repair of the branch pipe 6 of the buried pipe 1 will be described. As shown in FIG. 2, a repair pipe 3 is inserted into the buried pipe 1, and the repair pipe 3 is exposed at the lowermost portion of the branch pipe 6. A small opening 3b is opened in the blind portion 3a, the main body of the expansion bag 7 is inserted through the small opening 3b, and the mouth of the expansion bag 7 is pulled out from the small opening 3b. When the branch pipe 6 is near the end of the buried pipe 1, the expansion bag 7 may be inserted from the end of the buried pipe 1. The expansion bag 7 is a balloon-shaped bag made of a material such as rubber having high extensibility. Next, as shown in FIG. 3, an appropriate fluid such as air or water is injected into the expansion bag 7 to inflate it and pressed from the inside of the portion of the repair pipe 3 corresponding to the branch pipe 6 to make it made of synthetic resin. The repair pipe 3 is kept from being crushed by the pressing force of the repair branch pipe to be fused later.

Further, the expansion bag can be inserted from the end of the main pipe inserted into the repair pipe or another end thereof. In that case, it is not necessary to provide the repair pipe with a small opening. Further, as such a holding means, it is also possible to press the repair pipe from the inside with a fluid such as water or air.

On the other hand, a repair branch pipe 8 for a branch pipe having a shape as shown in FIG. 4 is separately prepared. The repair branch pipe 8 is made of the same or similar synthetic resin as the repair pipe 3 and can be joined to the repair pipe 3. Any material such as thermoplastic resin, thermosetting resin or fiber reinforced resin can be used as the material of the synthetic resin pipe as long as it can be joined, but from the viewpoint of price, corrosion resistance, workability (construction work), etc. Polyethylene resin is preferred. Further, the curvature of the lower joint portion 8a of the repair branch pipe 8 is three-dimensionally the same as the curvature of the outer circumference of the buried pipe 1.

Next, the joint portion 8a and the joint portion of the repair branch pipe 8
The portion of the repair pipe 3 with which the 8a abuts is heated by an appropriate method to locally melt, and the joint portion 8a is pressed against the blind portion 3a and fused. In this case, since the expansion bag 7 is present in the repair pipe 3, the repair pipe 3 is not softened and droops or is not crushed, and the repair branch pipe 8 can be reliably and firmly fused. If the material of the repair pipe 3 or the repair branch pipe 8 can be joined with an adhesive, such as vinyl chloride, a flange is attached to the lower surface of the joint portion 8a to reinforce the adhesive force. It is also possible to increase the adhesion area and bond with an adhesive. After joining the repair branch pipe 8 to the repair pipe 3 as described above, the fluid in the expansion bag 7 in the repair pipe 3 is drained to take out the expansion bag 7.

After joining the repair branch pipe 8 to the repair pipe 3, flanges 10 are attached to both ends of the buried pipe 1 cut before repair as shown in FIG.
Is attached, and the small opening 3b is closed. Next, water or air is supplied from the pressure supply port 11 into the pipe to increase the internal pressure of the pipe and perform a leak test.

If no abnormality is found in the leakage test, the curing agent is press-fitted from the curing agent tank 12 through the curing agent injection port 13 between the inner wall of the buried pipe 1 and the outer surface of the repair pipe 3. Air and residual water first come out from the hardening agent outlet 14 at the other end. By further continuing the injection of the curing agent, it is confirmed that the curing agent is sufficiently filled in the space between the buried pipe 1 and the repair pipe 3, and the curing agent injection port 13 and the curing agent outlet port 14 are closed. To do.
After the hardening agent hardens, the pressure in the repair pipe 3 is released.

Next, the blind portion 3a at the bottom of the repair branch pipe 8 is cut into a circular shape with a center drill or the like, so that the branch pipe portion can be repaired to the state shown in FIG.

In addition, as shown in FIG. 5, a connecting pipe 15 is prepared, and the openings of the buried pipe 1 are connected to each other. Further, the exposed portion of the buried pipe 1 and the outer surface of the connecting pipe 15 are subjected to anticorrosion treatment if necessary,
The excavation part is backfilled and the construction is completed.

[Effects of the Invention] As described above, according to the method of the present invention, it is not necessary to use a short pipe with a flange, and a synthetic resin pipe can be integrally inserted into an existing branch pipe, so that the construction is easy and quick. Can be done

Further, since a synthetic resin tube wall having a smooth inner surface and low resistance is formed, resistance to fluid is reduced, and corrosion in the tube can be effectively prevented.

Furthermore, according to the method of the present invention, it is possible to reduce the construction period and cost.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing a state in which a repair pipe is inserted into a buried pipe, FIG. 2 is a cross-sectional view of a branch pipe portion in which an expansion bag is inserted into the repair pipe, and FIG. 3 is a fluid injected into the expansion bag. FIG. 4 is a perspective view of the repair branch pipe, FIG. 5 is a schematic cross-sectional view showing a curing agent injection device and a connecting pipe, and FIG. 6 is a branch pipe part after repair. FIG. 1: buried pipe, 2 vertical shaft, 3: repair pipe, 3a: blind part, 3b: small opening, 6:
Branch pipe, 7: Expansion bag, 8: Repair branch pipe, 8a: Joint

Claims (3)

[Claims] 1. In a state in which a synthetic resin repair pipe is inserted into a main pipe portion of a pipe having a branch pipe, a synthetic resin repair branch pipe having a slightly smaller diameter than the branch pipe is inserted from the outside of the branch pipe. Then, after heat-sealing the repair branch pipe to the outside of the repair pipe while holding the original shape of the repair pipe by the original shape holding means, the inside of the gap between the repair pipe and the main pipe is filled with a curing agent or the like, Then, a blind part of the repair branch pipe is opened from the outside of the branch pipe. 2. The original shape holding means is provided with a small opening in a portion where the repair pipe is exposed at the lowermost portion of the branch pipe, and an expansion bag is inserted into the repair pipe through the small opening, and inside the repair pipe. Claims characterized in that when the repair branch pipe is heat-sealed to the repair pipe by inflating an expansion bag with a fluid, the original shape of the repair pipe is retained to ensure the heat-sealing. A method for repairing a pipe having the branch pipe according to item 1. 3. The original shape holding means inserts an expansion bag into a position corresponding to a branch pipe in the repair pipe from an end portion of the main pipe into which the repair pipe is inserted or another end portion of the main pipe, and a fluid is internally stored. The expansion bag is inflated by means of which the original shape of the repair pipe is held when the repair branch pipe is heat-sealed to the repair pipe to ensure the heat-sealing. A method for repairing a pipe having a branch pipe according to.